The invention relates to a device for determining a fuel split in at least one staged combustion chamber in a gas turbine or an aircraft engine, a gas turbine or an aircraft engine as well as an application of the same.
Staged combustion chambers are used in aircraft engines or gas turbines, wherein the pilot burners of the staged combustion chamber are constantly supplied with a minimum quantity of fuel. By contrast, the main burners of the staged combustion chamber are engaged only when increased performance is required. The ratio of pilot fuel flow to total fuel flow is referred to as the fuel split.
Downstream of a control valve unit that determines the total amount of fuel, a splitter valve unit is provided by means of which the total fuel mass flow can be variably distributed between the pilot burner and the main burner. The control valve unit and/or the splitter valve unit can be controlled by a propulsion-unit governor that provides the desired engine performance for controlling the splitter valve unit. Such a system is known from WO 95/17632 A1 or EP 1 079 179 B1, for example.
When it comes to controlling the valve units, ensuring operational safety is of primary importance. Further goals are the optimization of cost-efficiency and the reduction of emissions (e.g. NOx emission, smoke, unburnt hydrocarbons).